Benzenesulfonic acid, 2-methyl-, methyl ester → 2-benzyloxypropane

HRID 2406907Notes

Reaction equation

HRID 2406907 reaction equation
[C:1]1([CH3:12])[C:2](S(OC)(=O)=O)=[CH:3][CH:4]=[CH:5][CH:6]=1.[CH3:13][C:14](C)([O-:16])[CH3:15].[K+]>C1(C)C=CC=CC=1>[CH2:12]([O:16][CH:14]([CH3:15])[CH3:13])[C:1]1[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1

Participants

4

Reactant 2

HCID 90076Benzenesulfonic acid, 2-methyl-, methyl ester2×HCID 23665647Potassium tert-butoxide2×

Product 1

HCID 3474902-benzyloxypropane

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

1,3-diPEGoxy-2-benzyloxypropane [MW poly(ethylene glycol) (PEG)=9 kDa] (5.0 g, 0.55 mmoles) from Step A was placed in a two-necked round bottom flask and dissolved in 150 ml of toluene. The flask was fitted with a septum and a Dean-Stark trap and the compound was azeotropically dried under an inert atmosphere. The trap was replaced with a reflux condenser and the temperature of the flask was kept at 45° C. by placing the flask in a constant temperature oil bath. Methyl toluenesulfonate (1.62 ml, 5.4 mmoles) and 2.8 ml of potassium t-butoxide solution (1.0 M in THF) was added and the reaction stirred for 3 hours. Methyl toluenesulfonate (0.81 ml) and 1.4 ml of potassium t-butoxide solution were then added and the reaction was stirred for an additional 3 hours. The flask was removed from the oil bath and cooled to room temperature. The solution was transferred to a single-necked round bottom flask and the solvent was removed by rotary evaporation. The residue was dissolved in 5 ml of methylene chloride and precipitated by the addition of 50 ml of diethyl ether. The product was collected by filtration and dried under vacuum.

Workup

  1. customThe flask was fitted with a septum
  2. customa Dean-Stark trap and the compound was azeotropically dried under an inert atmosphere
  3. customThe trap was replaced with a reflux condenser
  4. customwas kept at 45° C.
  5. stirringthe reaction was stirred for an additional 3 hours
  6. customThe flask was removed from the oil bath
  7. customThe solution was transferred to a single-necked round bottom flask
  8. customthe solvent was removed by rotary evaporation
  9. dissolutionThe residue was dissolved in 5 ml of methylene chloride
  10. customprecipitated by the addition of 50 ml of diethyl ether
  11. filtrationThe product was collected by filtration
  12. customdried under vacuum

Sources & evidence

ORD record
ord-ea1272dfbddc46afb1d5840306db214b
Source dataset
uspto-grants-2014_08
Patent number
US08809453B2

Reaction notes

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